[GR-18163] Fix IO.select([io], nil, [io]) on macOS

PullRequest: truffleruby/4090

Author: eregon

CHANGELOG.md

@@ -11,6 +11,7 @@ Bug fixes:
 * Fix `Regexp.union` negotiating the wrong result encoding (#3287, @nirvdrum, @simonlevasseur).
 * Fix `Proc#parameters` and return all the numbered parameters lower than the used explicitly ones (@andrykonchin).
 * Fix some C API functions which were failing when called with Ruby values represented as Java primitives (#3352, @eregon).
+* Fix `IO.select([io], nil, [io])` on macOS, it was hanging due to a bug in macOS `poll(2)` (#3346, @eregon, @andrykonchin).
 
 Compatibility:
 

spec/ruby/core/io/select_spec.rb

@@ -114,6 +114,39 @@
   it "raises an ArgumentError when passed a negative timeout" do
     -> { IO.select(nil, nil, nil, -5)}.should raise_error(ArgumentError)
   end
+
+  describe "returns the available descriptors when the file descriptor" do
+    it "is in both read and error arrays" do
+      @wr.write("foobar")
+      result = IO.select([@rd], nil, [@rd])
+      result.should == [[@rd], [], []]
+    end
+
+    it "is in both write and error arrays" do
+      result = IO.select(nil, [@wr], [@wr])
+      result.should == [[], [@wr], []]
+    end
+
+    it "is in both read and write arrays" do
+      filename = tmp("IO_select_read_write_file")
+      w = File.open(filename, 'w+')
+      begin
+        IO.select([w], [w], []).should == [[w], [w], []]
+      ensure
+        w.close
+        rm_r filename
+      end
+
+      IO.select([@wr], [@wr], []).should == [[], [@wr], []]
+
+      @wr.write("foobar")
+      # CRuby on macOS returns [[@rd], [@rd], []], weird but we accept it here, probably only for pipe read-end
+      [
+        [[@rd], [], []],
+        [[@rd], [@rd], []]
+      ].should.include? IO.select([@rd], [@rd], [])
+    end
+  end
 end
 
 describe "IO.select when passed nil for timeout" do

src/main/java/org/truffleruby/platform/DarwinAArch64NativeConfiguration.java

@@ -750,6 +750,7 @@ public static void load(NativeConfiguration configuration, RubyContext context)
         configuration.config("platform.typedef.sae_connid_t", string(context, "uint"));
         configuration.config("platform.typedef.rlim_t", string(context, "ulong_long"));
         configuration.config("platform.typedef.rusage_info_t", string(context, "pointer"));
+        configuration.config("platform.typedef.nfds_t", string(context, "uint"));
         configuration.config("platform.typedef.pthread_t", string(context, "pointer"));
     }
 

src/main/java/org/truffleruby/platform/DarwinAMD64NativeConfiguration.java

@@ -749,6 +749,7 @@ public static void load(NativeConfiguration configuration, RubyContext context)
         configuration.config("platform.typedef.sae_connid_t", string(context, "uint"));
         configuration.config("platform.typedef.rlim_t", string(context, "ulong_long"));
         configuration.config("platform.typedef.rusage_info_t", string(context, "pointer"));
+        configuration.config("platform.typedef.nfds_t", string(context, "uint"));
         configuration.config("platform.typedef.pthread_t", string(context, "pointer"));
     }
 

src/main/java/org/truffleruby/platform/LinuxAArch64NativeConfiguration.java

@@ -863,6 +863,7 @@ public static void load(NativeConfiguration configuration, RubyContext context)
         configuration.config("platform.typedef.sa_family_t", string(context, "ushort"));
         configuration.config("platform.typedef.rlim_t", string(context, "ulong"));
         configuration.config("platform.typedef.rlim64_t", string(context, "ulong"));
+        configuration.config("platform.typedef.nfds_t", string(context, "ulong"));
     }
 
 }

src/main/java/org/truffleruby/platform/LinuxAMD64NativeConfiguration.java

@@ -863,6 +863,7 @@ public static void load(NativeConfiguration configuration, RubyContext context)
         configuration.config("platform.typedef.sa_family_t", string(context, "ushort"));
         configuration.config("platform.typedef.rlim_t", string(context, "ulong"));
         configuration.config("platform.typedef.rlim64_t", string(context, "ulong"));
+        configuration.config("platform.typedef.nfds_t", string(context, "ulong"));
     }
 
 }

src/main/ruby/truffleruby/core/io.rb

@@ -767,6 +767,21 @@ def self.select(readables = nil, writables = nil, errorables = nil, timeout = ni
         raise IOError, 'closed stream' if io.closed?
         io
       end
+
+      if Truffle::Platform.darwin? and !errorables.empty?
+        if errorables.all? { |obj| readables.include?(obj) or writables.include?(obj) }
+          # On macOS, if all errorables are in readables or writables, we make errorables empty,
+          # because if non-empty they cause a bug with macOS poll(2), detailed in
+          # https://github.com/oracle/truffleruby/issues/3346#issuecomment-1847323741
+          # Errors are still reported, POLLIN_SET and POLLOUT_SET both include POLLERR.
+          # POLLPRI is only for TCP OOB data (rare, not portable, poll(2) hangs on macOS with TCP OOB, another macOS bug),
+          # and other "high priority data" which seems to not exist or unused since there is no way to read that data.
+          errorables = []
+          errorable_ios = []
+        else
+          raise IOError, 'IO.select call on macOS with error IOs not in read IOs or write IOs, this is not supported due to poll(2) bugs on macOS'
+        end
+      end
     else
       errorables = []
       errorable_ios = []

src/main/ruby/truffleruby/core/posix.rb

@@ -199,7 +199,7 @@ def self.attach_function_eagerly(native_name, argument_types, return_type,
   attach_function :fsync, [:int], :int
   attach_function :ftruncate, [:int, :off_t], :int
   attach_function :getcwd, [:pointer, :size_t], :string
-  attach_function :ioctl, [:int, :ulong, :long], :int
+  attach_function :ioctl, [:int, :ulong, varargs(:pointer)], :int
   attach_function :isatty, [:int], :int
   attach_function :lchmod, [:string, :mode_t], :int
   attach_function :lchown, [:string, :uid_t, :gid_t], :int
@@ -215,8 +215,8 @@ def self.attach_function_eagerly(native_name, argument_types, return_type,
   attach_function :opendir, [:string], :pointer
   attach_function :pipe, [:pointer], :int
   # blocking=false for both poll because the timeout needs to be decreased on EINTR
-  attach_function :truffleposix_poll_single_fd, [:pointer, :long, :int], :int, LIBTRUFFLEPOSIX
-  attach_function :poll, [:pointer, :long, :int], :int
+  attach_function :truffleposix_poll_single_fd, [:int, :int, :int], :int, LIBTRUFFLEPOSIX
+  attach_function :poll, [:pointer, :nfds_t, :int], :int
   attach_function :read, [:int, :pointer, :size_t], :ssize_t, LIBC, true
   attach_function :readlink, [:string, :pointer, :size_t], :ssize_t
   attach_function :realpath, [:string, :pointer], :pointer
@@ -240,7 +240,7 @@ def self.attach_function_eagerly(native_name, argument_types, return_type,
   Truffle::Boot.delay do
     if NATIVE
       # We should capture the non-lazy method
-      attach_function_eagerly :poll, [:pointer, :long, :int], :int, LIBC, false, :poll, self
+      attach_function_eagerly :poll, [:pointer, :nfds_t, :int], :int, LIBC, false, :poll, self
       POLL = method(:poll)
     end
   end

tool/generate-native-config.rb

@@ -358,11 +358,14 @@ def initialize
   end
 
   def source(io)
-    io.puts '#include <stdint.h>'
-    io.puts '#include <stddef.h>'
-    io.puts '#include <sys/types.h>'
-    io.puts '#include <sys/socket.h>'
-    io.puts '#include <sys/resource.h>'
+    io.puts <<~C
+    #include <stdint.h>
+    #include <stddef.h>
+    #include <sys/types.h>
+    #include <sys/socket.h>
+    #include <sys/resource.h>
+    #include <poll.h>
+    C
   end
 
   def compile_command(source, target)